This invention relates to turbomachine design, and more specifically relates to the design of turbopumps.
Turbopumps have been employed for a wide range of applications, e.g., where it is required to pressurize and pump a fluid or gas from a supply source to be employed at an application destination. For example, turbopumps are commonly employed for pressurizing rocket engine fuel to be delivered to a rocket engine combustion chamber.
In a conventional turbopump configuration, there is in general provided a pump or compressor stage that is coupled to a turbine stage for providing power to the pump stage. Typically the pump and turbine stages are coupled in a configuration that enables efficient delivery of power from the turbine to the pump stage. For example, turbopump and turbine stages are commonly coupled through a common rotatable shaft or other transmission feature. Conventionally, the turbine stage is provided with a turbine rotor that is connected to the rotatable shaft or other power transmission feature, and the pump stage typically includes a rotational pumping system such as a pump rotor. When a fluid is directed to the turbine rotor, the turbine rotor rotates, causing the shaft to correspondingly rotate, and producing torque that is translated, via the shaft, into rotational pumping at the pump stage. A fluid provided to the pump stage is correspondingly pumped, and possibly pressurized, by the pump rotor, for delivery to the intended application. For purposes of this description, the term fluid is herein meant to refer to gases, liquids, and supercritical fluids
Although this conventional turbopump configuration has been found to be convenient for a wide range of macro-scale applications, it is not found to effectively enable many meso-scale and micro-scale applications that are becoming increasingly important and widely desired. Compact and highly mobile meso- and micro-scale thermodynamic and energy systems are important for applications such as powering and cooling of portable electronics, communications, and medical devices, control and modular propulsion of distributed and self-powered actuation and sensor systems, and thermodynamic cycling of distributed and/or auxiliary heating and ventilation systems, as well as many other applications. Typically, such applications optimally employ power sources and corresponding componentry that are characterized by high power and energy density but minimal size and weight, and that are cost effective.
Many such meso-scale and micro-scale applications that specifically require fluid and/or gas pumping or pressurization cannot easily accommodate a conventional turbopump configuration, yet require the pressurization and pumping work capabilities provided by such a configuration. For example, microelectromechanical systems (MEMs), which are typically produced by microfabrication materials and processes, do not in general accommodate a conventional turbopump configuration. Yet many MEMs applications, e.g., micro-energy and micro-power systems, cannot perform optimally without an ability to achieve high levels of pressurization and/or pumping of a fluid.